A Chili Pepper Fertilizer Guide

Proper fertilization can help chili pepper plants to be fruitful.

In most ways, and perhaps in virtually all, a chili pepper plant has the same growth requirements as do pepper plants in general. Peppers are tropical, heat-loving plants. Start them from seeds indoors in seed-starting trays or other containers, then move them out to the garden when the warm weather arrives. Each of the stages in the chili pepper growing process calls for somewhat different fertilizer applications.

Sowing

The seed germinating process for plants in general, and chili peppers specifically, is not heavily dependent upon soil-based nutrients. Even though chili pepper seedlings do need some nutrients to get started, most of these come from what the seed itself has stored. For this reason, most seed-starting mixes are fairly devoid of plant nutrients. They do provide physical support for the plant’s roots and a medium for delivering water, and that is all that is necessary early on. So, fertilizing at the seed-sowing stage is unnecessary and may even be detrimental.

Seedlings

During the seedling stage, when the chili pepper seedlings begin to grow and make their way toward maturity, they do need some nutrients. Pepper plants at this stage, however, should be fertilized only lightly. They are still relatively small and don't need a lot of nutrients. Fertilizers are labeled with three numbers representing the relative amounts of nitrogen, phosphorus and potassium in that order. At the seedling stage, choosing a liquid fertilizer with a 5-5-5 analysis and adding it sparingly to the starting tray's water would be beneficial.

Transplants

Once the seedlings have begun to grow significantly, and when conditions are warm enough in the garden, it's time to transplant them into their new home. At this stage -- because the plants are getting larger and because the goal is to get them to flower and bear fruit-- the chili pepper plants' nutrient requirements increase. A note of caution here is warranted, though: Too much nitrogen relative to other nutrients can stimulate the pepper plant to produce mostly stem and foliage at the expense of blossoms and fruit. To avoid this problem, fertilize the soil into which you’ll be setting out the transplants with a 5-10-10 fertilizer according to directions on the label prior to transplanting.

Maturing Plants

After the chili pepper plants have blossomed and have set a significant number of approximately grape-sized fruits, they’re likely ready for more fertilizer. Gardeners refer to the practice of applying fertilizer to the soil around individual plants as “side dressing.” At this maturing stage, it is appropriate to side dress with a fertilizer that has a higher analysis of nitrogen. A 5-3-3 fertilizer would serve, but still use some restraint. It’s important not to overdo it when fertilizing peppers. So apply on the conservative side of what the manufacturer’s label says for general garden usage. Depending upon weather conditions, limiting fertilization can have the effect of increasing capsaicin, the chili pepper’s heat-producing compound.

About the Author

Donald Miller has a background in natural history, environmental work and conservation. His writing credits include feature articles in major national print magazines and newspapers, including "American Forests" and a nature column for "Boys' Life Magazine." Miller holds a Bachelor of Science in natural resources conservation.